Regarding V-belt continuously variable transmission and toroidal continuously variable transmissions for vehicles, Tokkai Hei 5-126239 published by the Japanese Patent Office in 1993 discloses a method wherein a final target speed ratio is determined based on vehicle running conditions, such as engine load and vehicle speed, and the real speed ratio of the transmission is made to follow the final target speed ratio under a predetermined response.
More specifically, a transient target speed ratio is determined for every control cycle based on a deviation between the real speed ratio and final target speed ratio, and the speed ratio is feedback controlled to this transient target speed ratio.